/*
  Pangram is a sentence that contains all the letters in the alphabet
  https://en.wikipedia.org/wiki/Pangram
 */

const checkPangram = ( string ) => {
    if ( typeof string !== 'string' ) {
      throw new TypeError( 'The given value is not a string' )
  }

  const frequency = new Set()

  for ( const letter of string.toLowerCase() ) {
    if ( letter >= 'a' && letter <= 'z' ) {
      frequency.add( letter )
    }
  }

  return frequency.size === 26
}

export {
  checkPangram
}
